Light-emitting diode (LED) panel lamp is a kind of lighting device with characteristics such as ultra-thin thickness, ultra-bright light, super energy-saving property and environmental protection. It is mainly used in places required for energy-saving illumination with high color rendering index such as residences, hotels, public facilities, schools and hospitals. An existing LED panel lamp includes a metal shell in which a heat conduction circuit board, an LED lamp, a light reflecting film, a light guide plate and a diffusion plate are disposed. The diffusion plate and the light reflecting film are both connected with the light guide plate. The LED lamp is mounted on the heat conduction circuit board.